Complementary metal oxide semiconductor (CMOS) integrated circuits include n-channel metal oxide semiconductor (NMOS) transistors and p-channel metal oxide semiconductor (PMOS) transistors. The NMOS transistors and PMOS transistors are commonly formed in and on a crystalline silicon substrate. It may be desired to apply a first stress condition, for example tensile stress, to channel regions of the NMOS transistors and a different stress condition, for example compressive stress, to channel regions of the PMOS transistors. It may be desired to apply the separate NMOS and PMOS stress conditions in a way that requires only one photolithographic operation compared to CMOS integrated circuit fabrication sequences in which independent NMOS and PMOS stress conditions are not applied.